随着勘探开发地质环境日益复杂,特殊工艺井数量直线上升,随之而来的井壁稳定性问题引起了广泛关注。本文基于地质统计分析基础,提出了随钻预测定向井井壁稳定性分析方法。通过分析已钻井的地震、测井资料,采用地质统计中配置协同克里金以及序贯高斯模拟相结合的方法,预测出整个区块的三维岩石力学参数数据体,根据待钻井的轨迹,提取井眼轨迹处的岩石力学参数值,通过定向井坍塌、破裂和孔隙压力模型,建立相应的分层岩石力学预测模型,减少发生井壁失稳的可能性,同时可以和随钻测井资料对比预测结果的准确性,提高预测精度。

In recent years, with the increasing complexity of the exploration and development geological environment, the number of complex wells increases, and subsequently, the borehole stability becomes more and more an issue. This paper proposes a method to predict the borehole stability during drilling of directional wells based on a geological statistical analysis. Firstly, the seismic and logging data of drilled wells are analyzed, and then through the geostatistical collocated co-Kriging simulation combined with the sequential Gaussian simulation, the 3D data body of rock mechanics parameters for the whole block are predicted. According to the trajectory to be drilled, the parameters of rock mechanics for the wellbore trajectory are extracted and by using the models for collapse, fracture and pore pressure of the directional well, the prediction model for the corresponding stratified rock mechanics is built. The accuracy of the prediction can be evaluated in comparison with the logging data and by adjusting the parameters of the model, the model can be updated and refined to improve the prediction accuracy.